Intrauterine transfusion (IUT) was considered since the 1960s to manage fetal anemia.[1] There are mainly two methods, intraperitoneal and intravascular transfusion of blood. The commonly used transfusion circuit for IUT composes of syringe connected to three-way stopcock.[2] However, with this technique, one has to manually push the plunger of the syringe to transfuse the blood and rate of transfusion may vary time to time. This may even pose the risk of needle dislodgement due to accidental tugging of the line. The purpose of this article is to share our experience on how we carried out the procedure safely using a syringe infusion pump as opposed to a manual syringe that is typically used for IUT procedures.

Technical details

The proposed IUT apparatus is shown in [Figure 1]. Following are the components of the transfusion circuit:

Standard blood transfusion set with a roller clamp and a macroaggregate filter with pore size ranging between 170 and 230 um that has been spiked into packed red cell unit

Syringe Infusion Pump (Injectomat Agilia, Fresenius Kabi) a computer-controlled volumetric electro-mechanical infusion pump used to achieve controlled and precise delivery of packed red blood cells to the fetus. This unit can maintain flow rate between 0.1–200 mL/h with a precision of ±2%. It also comes with additional safety features such as dynamic pressure monitoring and antibolus mechanisms which allow a maximum of 0.2 mL release of fluid after obstruction is relieved. This degree of control and precision is unattainable with handheld syringes

A 50 cc syringe attached into the male port of the three-way stopcock

Three-way stopcock: With two female luer ports and a male luer lock with blood transfusion set connected to one female port

Extension tubing (150 cm): With the proximal end connected to the third port of the three-way stopcock and the distal end (left with the cap on) to be eventually connected to a amniocentesis needle after the entire circuit is primed with blood

Amniocentesis needle (Echo Tip, 20 gauge)

Ultrasound transducer.

Establishing uninterrupted flow without air bubbles in any part of the entire apparatus was done in three sequential steps as shown in [Figure 1].

Set the level of blood to half in the drip chamber of the blood transfusion set

Open the roller clamp completely and with negative suction from the syringe blood was drawn into the syringe along the track of dotted line (--1--)

Turn off the stopcock toward the blood transfusion set and blood is manually pushed to displace air from the entire length of the extension tubing along the track of dotted line (-.-2-.-). Step “b” is repeated to draw desired amount of blood into the syringe maintaining the closed system. The syringe is now ready to load into the infusion pump.

These steps in addition to avoiding air bubbles also eliminate dead volume in the entire circuit which helps ascertain the volume of blood infused in utero at any given time during the procedure with accuracy. Based on the tolerability of the fetus, the flow rate can be adjusted using the pump settings to achieve the controlled rate of transfusion. To verify the circuit safe for use, we validated the use of this circuit by checking plasma hemoglobin level of the blood sample collected from the tubing at the end of the procedure to ensure the circuit is safe for use.